278 
CAUSES OF THE DESTRUCTION OF THE FOREST. 
the American States it has been found necessary to protect, by 
special legislation, the lands through which they flow from the 
serious injury sometimes received through the practices I have 
described.* 
Special Causes of the Destruction of European Woods. 
The causes of forest waste thus far enumerated are more 
or less common to both continents; but in Europe extensive 
woods have, at different periods, been deliberately destroyed 
* Most physicists who have investigated the laws of natural hydraulics 
maintain that, in consequence of direct obstruction and frictional resistance 
to the flow of the water of rivers along their hanks, there is both an in¬ 
creased rapidity of current and an elevation of the water in the middle of 
the channel, so that a river presents always a convex surface. The lum¬ 
bermen deny this. They affirm that, while rivers are rising, the water is 
highest in the middle of the channel, and tends to throw floating objects 
shoreward ; while they are falling, it is lowest in the middle, and floating 
objects incline toward the centre. Logs, they say, rolled into the water 
during the rise, are very apt to lodge on the banks, while those set afloat 
during the falling of the waters keep in the current, and are carried 
without hindrance to their destination. 
Foresters and lumbermen, like sailors and other persons whose daily 
occupations bring them into contact, and often into conflict, with great 
natural forces, have many peculiar opinions, not to say superstitions. In 
one of these categories we must rank the universal belief of lumbermen, 
that with a given head of water, and in a given number of hours, a saw¬ 
mill cuts more lumber by night than by day. Having been personally 
interested in several sawmills, I have frequently conversed with sawyers 
on this subject, and have always been assured by them that their uniform 
experience established the fact that, other things being equal, the a-ction 
of the machinery of sawmills is more rapid by night than by day. I am 
sorry—perhaps I ought to be ashamed—to say that my scepticism has 
been too strong to allow me to avail myself of my opportunities of testing 
this question by passing a night, watch in hand, counting the strokes of a 
millsaw. More unprejudiced, and I must add, very intelligent and credi¬ 
ble persons have informed me that they have done so, and found the 
report of the sawyers abundantly confirmed. A land surveyor, who was 
also an experienced lumberman, sawyer, and machinist, a good mathemati¬ 
cian and an exact observer, has repeatedly told me, that he had very often 
“ timed ” sawmills, and found the difference in favor of night work above 
thirty per cent. Sed queere. 
